Introduction
 Supercapacitors (ECs) or ultracapacitors are being widely used for energy storage in many applications, such as portable electronic devices, and electrical vehicles etc.  The supercapacitor resembles a regular capacitor except that it offers very high capacitance in a small package.

Results and discussion
XRD patterns
(110) (101)

FTIR spectrum
Sn0.2 Co0.8O2

(211)

(112)(301)

Sn0.4Co0.6O2 % Transmittance
Sn0.2Co 0.8O2

(200)

Sn0.6Co 0.4O2

Sn0.4Co0.6O2

Intensity (A.U)

Sn 0.6Co 0.4O2

Sn0.8Co0.2O2 SnO2

Sn0.8Co0.2O2
1000 800 600

SnO 2

Wavenumbers (cm )

-1

400

20

30

40

50

60

70

80

2 theta (deg)

  The intensity of the diffraction peaks increases with the increase in the Co content, which indicates the enhancement of the crystallization of the materials

The peaks observed at 650, 603, 561 are typical for Sn-O stretching vibrations. Similarly the peak at 483 cm-1 corresponds to the Co-O-Co stretching mode, which is not available for the bare SnO2.

 Among all of the electrode materials, RuO2 exhibits a higher specific capacitance, good electrical conductivity and stability. However, the high cost and scarce material retarded its commercial acceptance  A cheap material with equivalent performance is required. Transition metal oxides have been considered as promising materials for supercapacitors.

 From the CV, a maximum capacitance of 840 F/g was obtained for the Sn0.6 Co0.4 O2.

Potential (V)

Conclusions Aim of the work
 To replace RuO2 with cheap transition metal oxide.  Cobalt doped tin oxide simples have been synthesized method by for Add 10 ml ethylene glycol followed by heating to dissolve hydrothermal 

 SnO2 and Cobalt doped SnO2 materials were prepared using low temperature hydrothermal method.  XRD reveals that the substitution of Co affects the crystal structure of SnO2 and increases the crystallization of the materials.  TEM images shows that SnO2 and Sn1-x CoxO2 particles are well developed and have spherical morphology with an average size of 2-4 nm.  Cyclic voltammetry curves show rectangular-like shape which reveals the capacitive behavior of the materials.

supercapacitor application. Supercapacitive behavior of Sn1-x CoxO2 evaluated samples by were cyclic Transferred to teflon autoclave and heated at 180 0C for 24h.

voltammogram (CV) in 1 M H2SO4 recorded at 10 mV/s scan rate. Sn1-x CoxO2 particles were separated by centrifuge and dried at 600 C for 12h